Method and means for exhibiting separate audio-visual records in synchronism



April 16, 1968 T. G. CUSTIN METHOD AND MEANS FOR EXHIBITING SEPARATEAUDIO-VISUAL RECORDS IN SYNCHRONISM 2 Sheets-Sheet 1 Original Filed Dec.27, 1961 MAGNETIC SOUND TAPE 5TRETCHED UNDER LENGTHWISE TENSION @MMKQV77mm: 5 [whiz Apnl 16, 1968 T. G. CUSTIN 3,373,328

METHOD AND MEANS FOR EXHIBITING SEPARATE AUDIO-VISUAL RECORDS INSYNCHRONISM Original Filed Dec. 27, 1961 2 Sheets-Sheet @MMV Ham: 6". [251222 United States Patent 3,378,328 METHOD AND MEANS FOR EXHIBITINGSEPARATE AUDIO-VISUAL RECORDS IN SYNCHRONISM Thomas G. Custin, Rte. 3,Doyle Road, Baldwinsville, N.Y. 13027 Original application Dec. 27,1961, Ser. No. 162,419, now Patent No. 3,240,329, dated Mar. 15, 1966.Divided and this application Sept. 8, 1965, Ser. No. 485,889

7 Claims. (Cl. 352-31) This invention relates to talking motion picturesand refers more particularly to a method and apparatus for producing andexhibiting a combined visual-audio recording of the type comprising aconventional motion picture film on which a visual record is carried anda magnetic tape which is separate from the film but interwound therewithand on which a sound record is carried; and the invention relates moreparticularly to a method and apparatus for producing or for projectingand reproducing, the audio and visual components of such a recordsimultaneously, so as to achieve a talking motion picture having itssound synchronized with the picture.

This invention is a division of my co-pending application, Ser. No.162,419, filed Dec. 27, 1961, now Patent No. 3,240,329, in which thecombined audio-visual recording is claimed.

Magnetic recording tape has several features that render it especiallysuitable as a motion picture sound recording medium for amateur use, andeven for many professional purposes. The low cost of the tape itself andof the recording and playback equipment used with it, the absence of anyrequirement for processing between recording and playback, the ease withwhich erasures and re-recordings can be made, and the flexibility,durability and compactness of magnetic tape are all desirable in amotion picture sound recording medium.

Heretofore, however, where magnetic tape has been used for this purposeit has usually been bonded to the motion picture film, along one sideedge portion thereof, in order to insure synchronization of sound andpictures during projection. The bonding of the tape to the film requiredspecial processing, usually beyond the facilities of the amateur, butthis was not the only disadvantage of securing the tape to the film.Since there is a minimum feasible width for magnetic tape, and it isimportant that the tape not extend laterally into the picture area ofthe film, there is a practical lower limit to film size for a compositevisual-audio record strip in which magnetic tape is secured to the film.As a rule, therefore, sound motion pictures have not heretofore beenavailable in film sizes below 16 mm. 7

Since 8 mm. motion picture film is used by the majority of home moviemakers, there has been a very substantial unsatisfied demand for soundmotion pictures using 8 mm. film for the pictorial record and magnetictape for the sound record medium.

Some amateurs have of course used magnetic tape and tape playbackapparatus in conjunction with their projector to provide backgroundmusic or a commentary for their films, but they have almost invariablyin such cases wished more or less vainly that they could achieve perfectsynchronization between the taped sound and the motion picture. Whileapparatus has been devised for locking a separate tape drive intosynchronism with a motion picture projector, such apparatus hasheretofore been prohibitively expensive for the amateur and has notenjoyed widespread use.

With the foregoing in mind it is a general object of this invention toprovide a composite audio-visual strip record, and a method andapparatus for projecting the 3,378,328 Patented Apr. 16, 1968 same todisplay a talking motion picture, wherein the visual record comprisesmotion picture film of any desired width, and the sound record mediumcomprises standard readily available magnetic tape not secured to thefilm, and wherein the apparatus includes conventional projection meansfor the film, a generally conventional transducer or pickup head for themagnetic recording tape, and very simple and inexpensive means forcausing the film and magnetic tape to progress through the apparatus insynchronism with one another.

In connection with the object just stated, it is another object of thepresent invention to provide a method and apparatus for projecting acomposite audio-visual strip comprising a motion picture film and amagnetic recording tape which is unattached to the film along its lengthbut which is interwound on the same reel with the film, and for keepingthe film and tape synchronized through successive projections andrewindings.

I am aware that the interwinding of separate strip-like audio and visualrecords on a common reel has been proposed heretofore, notably in DeForest Patent No. 1,843,972, which discloses apparatus intended for usewith a record comprising a picture film and a separate sound track filmthat is interwound on the same reel with the picture film, and in WarrenPatent No. 2,962,927, which discloses a projector having an interwoundpicture film and sound tape on its supply reel. However, the De Forestand Warren patents evidence a lack of appreciation of certainfundamentals which I have discovered and which are essential to thesuccessful operation of apparatus using separate sound and picturestrips interwound on a common reel.

When two strips of motion picture film or other substantially inelasticand similar materials are interwound on a supply reel, with layers ofone strip alternating with layers of the other, each convolution of theouter strip must have a slightly greater circumferential length than theconvolution of the other strip which it directly overlies, due to theslightly greater radius on which the outer strip is wound. Hence thestrip that has its convolutions outermost must have a greater totallength than the inner one, and as the supply reel rotates the two stripswill come off of it in unequal lengths. Unless the strips are progressedthrough the projector at unequal speeds (an arrangement that wouldrequire elaborate synchronizing apparatus) the shorter strip willcontrol the speed of rotation of the supply reel, and the longer willfall slack as it comes ofi of said reel.

If the two strips are arranged in synchronized relation on the supplyreel, synchronization will of course be lost as soon as such slackdevelops. Subsequent rewinding of the strips from the takeup reel backonto the supply reel will merely aggravate their unsynchronizedrelationship unless some highly specialized rewinding arrangement isemployed.

The present invention contemplates the projection and rewinding of acomposite visual-audio record comprising a motion picture film and amagnetic sound tape which is separate from the film but interwoundtherewith on a common reel, and in overcoming the problems heretoforeposed by that arrangement this invention takes advantage of theelasticity which is inherent in certain widely used types of magneticrecording tapes, namely those having a polyester base. It is of theessence of the invention that the tape and motion picture film be sointerwound On the reel that the tape is always outermost in eachconvolution of the composite film-tape record strip, and that the tapeis under greater lengthwise tension than the fil'r'n. Because of thetension under which it is maintained on the reel and its greaterelasticity, the

tape, although having the same length as the film when unstretched, isstretched on the reel to a greater length than the film, and thusaccommodates itself to the larger radii on which it is wound.

When the tape is drawn off of the reel it of course resumes verypromptly its normal unstretched lengt and hence assurance is had thatequal lengths of tape and film will pass through the projectionapparatus in a given time, thereby producing perfectly synchronizedsound and pictures.

Bearing in mind these essential requirements of the composite striprecord, it is another object of this invention to provide projectionapparatus for displaying such a record wherein the film and tape areprogressed through the apparatus along separate paths which respectivelycarry them past projection means and a tape pickup head, but are at alltimes drawn along their paths at equal linear speeds so as to bemaintained 1n synchronized lengthwise relationship to one another, andwhereby the film and tape are recombined in intcrwound relationship on atakeup reel, with the tape again outermost and under tension and stillin synchronized lengthwise relationship to the film.

Another object of this invention, providing a feature having particularappeal to amateurs, resides in the provision of apparatus for projectingfilm and tape that are interwound on a supply reel in the mannerdescribed, through which apparatus both film and tape can be threadedvery simply and easily, in a generally conventional manner, and whichapparatus also makes possible the rewinding of film and tape from thetakeup reel onto the supply reel in a generally conventional manner.

Thus it is a further object of this invention to provide unusuallysimple and inexpensive projection apparatus, particularly well suitedfor use by amateurs and excellently adapted for use with the popular 8mm. film, whereby a magnetic sound recording, made either during orafter photography, can be automatically run in perfect synchro-nism witha motion picture record on film, and can be maintained in suchsynchronism despite repeated projections and rewindings.

Another object of this invention resides in the provision of a soundmotion picture apparatus of the character described that incorporatesvery simple means for constraining motion picture film and magneticsound recording tape to move at identical linear speeds through theapparatus, from a supply reel on which they are interwound and onto atakeup reel on which they are again interwound, and by which the tape istensioned as it moves onto the takeup reel to stretch it to the extentnecessary to cause it to feed smoothly onto the takeup reel and maintainits pre-established lengthwise relationship with the film.

For many purposes it is satisfactory to prepare a sound record intendedto accompany a motion picture after the motion picture film has beenexposed and developed, the sound being recorded during projection of thefilm. It will be apparent from what has been said above that the motionpicture projector of this invention lends itself very well to thismanner of preparing a sound record, providing the magnetic transducer orpickup head in the projector is selectively reconnectable for eitherrecording or playback, as is usually the case.

However, the principles of the invention are also applicable to a soundmotion picture camera in which the sound record is made simultaneouslywith exposure of motion picture film; and it is thus another object ofthis invention to provide a method and apparatus for producing acomposite audio-visual strip of the character described, capable ofbeing embodied in a camera having a very simple mechanism and which canbe very light and compact even though such camera includes all of thenecessary sound recording equipment.

With the above and other objects in view which will appear as thedescription proceeds, this invention resides in the novel method andconstruction, combination and arrangement of parts substantially ashereinafter described and more particularly defined by the appendedclaims, it being understood that such changes in the precise embodimentof the hereindisclosed invention may be made as come within the scope ofthe claims.

The accompanying drawings illustrate one complete example of thephysical embodiment of the invention constructed according to the bestmode so far devised for the practical application of the principlesthereof, and in which:

FIGURE 1 is a more or less diagrammatic cross-sectional view of a reelon which are interwound separate strips of motion picture film andmagnetic tape comprising the composite audio-visual strip of thisinvention;

FIGURE 2 is a diagrammatic side elevational View of sound motion pictureprojection apparatus embodying the principles of this invention andsuitable for use with the audio-visual record shown in FIGURE 1;

FIGURE 3 is a detail perspective view on an enlarged scale of thesprocket wheel of the projector shown in FIGURE 2, illustrating how thefilm and tape are trained thereover;

FIGURE 4 is a more or less diagrammatic side eleva tional view of rewindapparatus that can be used with the audio-visual record shown in FIGURE1 and the projector illustrated in FIGURE 2, portions of the reels beingbroken away; and

FIGURE 5 is a view similar to FIGURE 3 but illustrating a modifiedembodiment of the invention.

Referring now more particularly to the accompanying drawings, thenumeral 5 designates generally an audiovisual record of this inventioncomprising generally a reel 6 upon which is wound a composite strip 7consisting of a length of motion picture film 8 and a length of magneticrecording tape 9. The motion picture film is in all respectsconventional, and may have any desired width, from the popular 8 mm.size upwardly. The film is of course provided with sprocket holes 10that are spaced at regular intervals along its length, in apredetermined relationship to each pictorial frame on the film, and bywhich the film is advanced lengthwise through a projector when beingexhibited.

The magnetic recording tape 9 is likewise of a readily availablecommercial type, but is of a stock which has a substantial degree ofelasticity. Polyester base magnetic tape (sometimes appearing under thetrademark Mylar) possesses the necessary elasticity, and generally thethinnest polyester base tape is the most satisfactory for the purposesof this invention, since it stretches most easily. Thus /2 mil Mylarbase tape has afforded excellent resuits in practice, although 1 milpolyester base tape has also been found satisfactory. The magnetic tapecan be modified if desired, by the provision of lengthwise spaced apartsprocket holes 10' (see FIGURE 5) corresponding in dimensions andspacing to the sprocket holes in the film. However, it is preferred touse imperforate tape in exactly the form in which it is suppliedcommercially.

The reel 6 upon which the composite strip 7 is wound is likewise aconventional motion picture film reel, having a hub 11 provided with aslit 12 in which the inner end of a film can be engaged, and sideflanges or discs 13 which engage the edges of film being wound onto thehub to guide the film smoothly onto the reel so that it forms a compactcoil. In this case the magnetic tape 9 and motion picture film 8 areinterwound on the reel so that layers of film and tape alternate fromthe hub of the reel outwardly, and both can have their inner endportionsengaged in the slit 12.

The record carrying portions of the film and tape are of equal lengthwhen the tape is unstretched. Obviously both film and tape can have suchlengths of unrecorded leader at one or both ends as may be desired tofacilitate threading them through a projector and as may be necessary tostart them through the projector in synchronism.

The composite strip 7 is so wound on the reel 6 that the tape portionassociated with a given part of the film lies radially outwardly of thefilm in each convolution on the reel and hence embraces a slightlygreater circumference. By reason of the construction of the projectionapparatus, hereinafter described, with which the record 5 is used, thetape on the reel 6 is under a substantial degree of lengthwise tension,sufiicient to stretch it to the extent necessary to compensate for theslightly greater radii on which it is wound. Hence the composite striplies very smoothly on the reel, with no gaps or bulges that might causethe tape and film to lose synchronism during their progress through theprojector. Friction between the tape and film is entirely adequate toprevent the tape from returning to its normal unstretched length when itis coiled on the reel even though the outer ends of the film and tapemay be free.

The projector used with the record 5 for exhibiting the latter is inmany respects conventional. It includes a suitable supply reel support21 on which a supply reel 22 can be detachably mounted for substantiallyfree rotation, and a takeup reel support 23 on which a takeup reel 24can be readily detachably mounted.

Motion picture film drawn off of a supply reel on the supply reelsupport passes through generally conventional projection means 25 in themachine that includes the usual geneva movement or the like by which thefilm is advanced one frame at a time, in a series of rapid intermittentmovements, through a film gate 27 and between a lamp 28 and a lens 29. Asuitable motor (not shown) drives the geneva movement and the usualshutter (not shown) associated therewith, and also drives sprocketwheels 30 and 31 over which the film is trained.

The sprocket wheels 30 and 31 are rotated at a steady rate which issynchronized with the rate of motion of the geneva movement. Thesprocket wheel 31, which is located along the path of film movementbetween the supply reel and the film gate, serves to draw film off ofthe supply reel and thus relieves film tension on the geneva movement.Since this sprocket wheel progresses the film at a smooth, steady rate,but the film advances through the film gate in a series of rapid jerks,conventional slack film loops 32 are formed above and below the filmgate when the film is threaded therethrough, the projector beingprovided with any conventional guide means (not shown) for definingloops of the proper size.

At this point it should be observed that the sprocket wheel 30 isrotated at the same rate as the sprocket wheel 31 and in synchronismwith the rate of motion of the geneva movement, and that the takeup reel24 is driven, through a belt clutch 33 or the like, in such a mannerthat film tends to be drawn onto the takeup reel at a faster linearspeed than the sprocket wheel 30 allows it to advance. The retardingeffect thus exerted by the sprocket wheel 30, through the film, holdsdown the rotational speed of the takeup reel to exactly that required topick up the film as fast as it comes out of the projector, but imposes atension upon the film as it goes onto the takeup reel which insures thatthe film will lie smoothly on the reel, with each convolution snuglyfiatwise overlying the one therebeneath, and with no gaps or bulges inthe coil being wound onto the reel.

The projector 20 also includes a conventional transducer or magnetictape head, generally designated 36, which can have the usual erase andrecording gaps, the latter serving also for playback. A pressure pad 37opposite the transducer urges tape into running engagement therewith ina known manner. It will be understood that the transducer or head 36 isconnected with an amplifier and a speaker, neither of which is shown.

'From the supply reel 22 to the sprocket wheel 30 to the magnetic tapeelement 9 of the opposite audio-visual strip 7 follows a path throughthe projector which is separate from that traversed by the film element;and of course the path of the tape takes it through the transducer 6 36.As it comes off of the supply reel the tape preferably first passes overa series of idlers 39, which are mounted at fixed locations on theprojector so spaced apart as to insure that the paths of film and tapebetween the supply reel and the sprocket wheel 30 will be of equallengths. This allows equal lengths of starting leader to be used on thefilm and tape. To the same end the tape head is preferably so located onthe projector that the distance along the path of tape travel from thesupply reel to the head is equal to the distance along the film pathfrom the supply reel to the projector. means 25.

Attention is directed to the fact that the idler 39 which is nearest thesupply reel along the path of tape travel is so located that thecomposite strip comes off of the supply reel with the tape alwaysradially outermost, this being an essential feature of the presentinvention which in part accounts for the successful synchronization ofsound and pictures as the tape and film move along their separate pathsthrough the machine.

After moving across the idlers '39 and through the head 36, the tape canbe twisted through and carried around one side of the lens and filmgate, as at '40. A suitable idler 41 or a smooth trough-like stationaryguide element can be provided for this purpose. The tape then passesacross another guide element 42 by which it is untwisted, and is thencetrained around the sprocket wheel 30, fiatwise overlying the filmtrained thereover.

Preferably, guide idlers 4:4 and 45 are mounted at substantiallydiametrically opposite sides of the sprocket wheel 30, and the tape andfilm are trained under them to insure an adequate wrap of tape and filmaround the sprocket wheel.

The tape traverses the sprocket wheel 30 alongside the sprocket teeththereon, and thus overlies the main body of the film on which thepictorial frames are carried, with the tape in good surface-to-surfaceengagement with the film. This relationship of film and tape on thesprocket wheel is noteworthy, since it affords a frictional drive bywhich the film draws the tape through the head 36 at a lineal speedwhich is always and necessarily equal to the lineal speed at which thefilm is progressed by the sprocket wheels, thus insuring the perfectsynchronization of sound and pictures that is one of the objects of thisinvention. The frictional drive between the film and tape also allowsthe sprocket wheel 30 to hold back the tape, against the tendency of thetakeup reel to draw it along at a faster linear speed than that at whichthe sprocket wheel allows it to progress, thus tensioning the tape as itgoes onto the takeup reel.

The tape, like the film, moves directly onto the takeup reel 24 from thesprocket wheel 30. It is another essential feature of the projector ofthis invention that the composlte strip goes onto the takeup reel withthe tape outermost. This arrangement insures that in each convolution ofthe composite strip on the takeup reel the tape will be wound on aslightly greater radius than the film. The necessary additional lengthof tape to accommodate it to this larger radius is of course obtained bylengthwise stretching of the tape as it goes from the sprocket wheel 30onto the takeup reel, due to the tension to which the tape is subjectedby the takeup reel and the sprocket wheel 30.

It will be noted that the cooperation between the sprocket wheel 36 andthe takeup reel 24 automatically maintains the tape tension force atjust the required value to effect the exact amount of tape stretchrequired for smooth winding, so that the tape and film are wound ontothe takeup reel with their lengthwise corresponding portions in the samerelation to one another that they came off of the supply reel.

Rewinding of the composite strip is accomplished in the conventionalmanner illustrated in FIGURE 4, which shows a rewind mechanism suitablefor use with the audio-visual record of this invention. Whileillustrated as a separate mechanism, the rewind device obviously could(and usually would) comprise the projector itself, with its drivemechanism reconnected for rewinding in a com pletely conventionalmanner.

In any event the rewind mechanism must be so arranged that the compositestrip comes off of the takeup reel with the tape outermost and goes ontothe supply reel with the tape still outermost. In this Way the requiredstretch is imparted to the tape as it is rewound onto the supply reel,so long as the film is under some slight tension as it moves from onereel to the other. In most cases such tensioning of the film is efiectedautomatically during rewinding because only the supply wheel isrotatably driven, the film is relied upon to drive the takeup reel, andthe takeup reel is steadily and constantly accelerated during therewinding process as the diameter of the coil thereon decreases whilethe diameter of the coil on the supply reel is increasing. Inasmuch asthe film is thus tensioned during rewinding, the tape will be likewisesubjected to the required amount of lengthwise tension, and this willoccur automatically even though the rewindin-g process is completelyconventional.

The conventional rewinding operation made possible by this invention isanother feature which particularly commends it to amateurs, since itrequires no change in the rewinding practices and habits to which theyhave become accustomed with silent film.

Initially, for recording a sound program on the tape, the tape andexposed, developed film can be fed into the projector from separatereels to be interwound on the takeup reel. Thereafter the film and tapewill of course remain in properly synchronized relationship duringsubsequent rewinding and projection.

Preferably the start and finish end portions of the tape and film aredetachably secured together, as by means of pressure sensitive tape orthe like, so that the film and tape will always be in the desiredlengthwise relationship to one another that maintains synchronization ofthe sound and picture records. If the projector is arranged to allow thefilm and tape to be inserted edgewise into the several guides androllers through which they are threaded, as is a common practice, aleader of the composite strip can then be readily drawn off of thesupply reel and caught in the slot 12 in the hub'of the takeup reel,after which the film and tape, in that order, can be separately threadedthrough the projector mechanism. Adhesion to one another of the finishends of the film and tape strips similarly facilitates rewinding becausethe composite strip can be handled as a unitary length of material infastening the trailing ends back into the supply reel.

As illustrated in FIGURE 5, the magnetic tape can be provided withlengthwise spaced apart sprocket holes 10' near one side edge thereof,adapted to be engaged by the teeth 47 on the sprocket wheel 39.Obviously such perforated tape could be trained over a separate sprocketwheel rotatably driven in synchronism with that over which the film istrained. Other simple arrangements for constraining the tape and film tomove toward the takeup reel at equal linear speeds will readily occur tothose skilled in the art.

It will be apparent that the principles of the projector illustrated inFIGURE 2. are readily applicable to a camera in which unrecorded tapeand unexposed film are interwound on a common supply reel and pass to acommon takeup reel upon which they are again interwound. The tape headitself and the amplifier required for it can be very simple, light andcompact when built in accordance with known designs, and only arelatively small battery pack would be required for electric power forthe sound recording equipment. Such a camera would obviously have littlemore Weight and bulk than a silent camera for the same size film.Obviously the interwound sound and tape on the takeup reel would have tobe separated during development of the film, but they could be readilyrecombined in a projector, as pointed out above, without the slightestloss of synchronism.

To avoid the necessity for separating the film and tape in the filmprocessing laboratory, the two could be wound onto separate takeup reelsin the camera, at some expense of compactness; and if compactness were aless important consideration than the utilization of completely standardcommercially available material the camera could also provide forseparate supply reels of film and tape. In any event, it is onlynecessary that some means be provided in the camera for progressing filmand tape therethrough at the same linear speeds, and such means can beidentical with those herein disclosed for accomplishing the same resultin a projector.

From the foregoing description taken together with the accompanyingdrawings it will be apparent to those skilled in the art that thisinvention provides a composite audiovisual record wherein the soundrecord medium consists of commercially available magnetic tape and thepicture record medium consists of ordinary motion picture film of anydesired size with which the tape is interwound on a common reel, butwhich is otherwise separate from the tape. It will also be apparent thatthe projector apparatus of this invention, for exhibiting saidaudio-visual record, is relatively very simple and inexpensive, beingbasically a modification of a conventional motion picture projector towhich has been added a suitable magnetic tape head and suitable meansfor guiding tape along a path separate from that followed by the film,from a supply reel, through the pickup head, to a point at which thetape and film are together fed onto a takeup reel in the properrelationship. Thus the present invention affords a talking motionpicture apparatus which is in every respect well adapted to the amateurbut which, despite its simplicity and low cost, is nevertheless suitablefor many professional purposes.

What is claimed as my invention is:

1. In combination with sound motion picture apparatus of the typecomprising a transducer head for magnetic tape sound recordings and filmguiding and advancing means for moving motion picture film along adefined path from a supply reel, through means for intermittently movingthe film past a lens, and onto a takeup reel:

(A) tape drive means synchronized with the film advancing means forconstraining magnetic tape to move along a defined path from the supplyreel through the transducer head and to the takeup reel at the samelinear speed at which film moves from the intermittent motion means tothe takeup reel;

(B) tape draw-off guide means defining a path for magnetic tapeinterwound on the supply reel with film, along which path tape moves,separately from film, from the supply reel through the transducer headand to the tape drive means, the path defined by said tape draw-offguide means being outwardly relative to the supply reel from the pathfollowed by film leaving the supply reel; and

(C) tape windup guide means defining a path along which tape moves fromthe tape drive means to the takeup reel and which path lies outwardlyrelative to the takeup reel from the path of film being wound thereonto,so that the tape can be interwound with film on the takeup reel, and asa result of being wound outermost be tensioned lengthwise to a greaterextent than the film.

2. The apparatus of claim 1, further characterized by the fact that saidtape drive means comprises a member having a curved surface over whichfilm moving from the intermittent motion means to the supply reel can betrained and over which magnetic tape can be trained in frictionalsurface-to-surface contact with film, with the tape radially outermost,so that the tape is drawn around said surface by the film therebeneatn,and at the same linear velocity as the film.

3. The apparatus of claim 1, wherein said member comprises a rotatablydriven sprocket roller comprising a part of the film advancing means,having teeth adapted to 9 engage in sprocket holes in film, and by whichthe film is constrained to move from the intermittent motion means tothe takeup reel at a substantially uniform linear velocity.

4. The apparatus of claim 1, wherein said tape drive means comprises asprocket roller having teeth engageable in regularly spaced sprocketholes in magnetic tape, and means for rotata'bly driving said sprocketroller in synchronism with the film advancing means.

5. In combination with motion picture apparatus having supports for asupply reel and a driven takeup reel and means defining a path alongwhich motion picture film is moved from a supply reel on the supply reelsupport to a takeup reel on the takeup reel support, by way ofintermittent motion means and a steady motion sprocket Wheel by whichthe film is constrained to move lengthwise at a substantially constantrate such that it is wound onto the takeup reel under tension:

(A) a magnetic tape transducer head;

(B) means for constraining tape to move lengthwise through thetransducer head at the same linear speed at which the sprocket wheeldrives the film, so that the passage of tape through the transducer headis at all times synchronized with the passage of film through theprojection means;

(C) tape draw-off guide means defining a path for magnetic tape from asupply reel on the supply reel support through the transducer head andto the drive means, which path is separate from that for film and liesoutwardly of the film path adjacent to the supply reel; and

(D) tape rewinding guide means for conducting tape along a path from thetape drive means to a takeup reel on the takeup reel support, which pathlies outwardly of the takeup reel relative to the film path so that thetape and film are rewound on the takeup reel in interwound relationshipwith the tape outermost and therefore under a greater lengthwise tensionthan the film so as to be stretched to accommodate the tape to thegreater radii on which it is wound.

6. The motion picture film projection apparatus of claim 5, furthercharacterized by the fact that said means for constraining the tape tomove at the same linear speed at which the sprocket wheel moves the filmcomprises a portion of the tape guide means by which tape is trainedover the sprocket wheel to ride upon the outer surface of film trainedthereover, so that the tape is drawn along said defined tape path by itsfrictional engagement with film.

7. The method of transferring from one reel to another a compositeaudio-visual record that comprises a motion picture film carrying apictorial record and a magnetic sound tape having substantial elasticityand which is interwound with the film on said one reel with layers oftape and film alternating and the convolutions of the tape outermost,and with the tape under such tension that it is stretched to the extentnecessary to accommodate the larger diameters on which it is wound sothat corresponding portions of the tape and film have equal lengths andare in a predetermined lengthwise relation to one another along theirconvolutions, said method comprising:

(A) withdrawing the tape and film simultaneously from said one reel,both at the same rate and with the tape outermost; a

(B) winding the film onto said other reel at the same rate that it iswithdrawn from the first mentioned reel, and while maintaining tensionon it;

(C) simultaneously with winding the film onto said other reel, windingthe tape onto said other reel in convolutions which alternate with thoseof the film and are outward of them; and

(D) constraining the tape to move onto said other reel at the samelinear speed as the film, so that as the tape goes onto said other reelit is tensioned and elastically stretched to the extent necessary toaccommodate the larger diameters on which its convolutions are wound, tothereby provide for the maintenance of said predetermined lengthwiserelationship between corresponding portions of the tape and film.

References Cited UNITED STATES PATENTS 1,843,972 2/1932 De Forest 352-312,962,927 12/1960 Warren 352 --34 JULIA E. COINER, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,378,328 April 16, 1968 Thomas G Cust1n I It is certified that errorappears in the above identified patent and that said Letters Patent arehereby corrected as shown below:

Column 5, line 71, cancel "to", second occurrence; line 72,1 "0pp0site"should read composite qgf 4a Signed and sealed this 9th day of September1969;?

(SEAL) Attest;

Edwin-d M. Fletcher, Jr.

Commissioner of Patents Attesting Officer WILLIAM E. SCHUYLEILJR.

1. IN COMBINATION WITH SOUND MOTION PICTURE APPARATUS OF THE TYPECOMPRISING A TRANSDUCER HEAD FOR MAGNETIC TAPE SOUND RECORDINGS AND FILMGUIDING AND ADVANCING MEANS FOR MOVING MOTION PICTURE FILM ALONG ADEFINED PATH FROM A SUPPLY REEL, THROUGH MEANS FOR INTERMITTENTLY MOVINGTHE FILM PAST A LENS, AND ONTO A TAKEUP REEL: (A) TAPE DRIVE MEANSSYNCHRONIZED WITH THE FILM ADVANCING MEANS FOR CONSTRAINING MAGNETICTAPE TO MOVE ALONG A DEFINED PATH FROM THE SUPPLY REEL THROUGH THETRANSDUCER HEAD AND TO THE TAKEUP REEL AT THE SAME LINEAR SPEED AT WHICHFILM MOVES FROM THE INTERMITTENT MOTION MEANS TO THE TAKEUP REEL; (B)TAPE DRAW-OFF GUIDE MEANS DEFINING A PATH FOR MAGNETIC TAPE INTERWOUNDON THE SUPPLY REEL WITH FILM, ALONG WHICH PATH TAPE MOVES, SEPARATELYFROM FILM, FROM THE SUPPLY REEL THROUGH THE TRANSDUCER HEAD AND TO THETAPE DRIVE MEANS, THE PATH DEFINED BY SAID TAPE DRAW-OFF GUIDE MEANSBEING OUTWARDLY RELATIVE TO THE SUPPLY REEL FROM THE PATH FOLLOWED BYFILM LEAVING THE SUPPLY REEL; AND (C) TAPE WINDUP GUIDE MEANS DEFINING APATH ALONG WHICH TAPE MOVES FROM THE TAPE DRIVE MEANS TO THE TAKEUP REELAND WHICH PATH LIES OUTWARDLY RELATIVE TO THE TAKEUP REEL FROM THE PATHOF FILM BEING WOUND THEREONTO, SO THAT THE TAPE CAN BE INTERWOUND WITHFILM ON THE TAKEUP REEL, AND AS A RESULT OF BEING WOUND OUTERMOST BETENSIONED LENGTHWISE TO A GREATER EXTENT THAN THE FILM.